skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on March 1, 2019

Title: Hg isotopes reveal in-stream processing and legacy inputs in East Fork Poplar Creek, Oak Ridge, Tennessee, USA

In this paper, natural abundance stable Hg isotope measurements were used to place new constraints on sources, transport, and transformations of Hg along the flow path of East Fork Poplar Creek (EFPC), a point-source contaminated headwater stream in Oak Ridge, Tennessee. Particulate-bound Hg in the water column of EFPC within the Y-12 National Security Complex, was isotopically similar to average metallic Hg(0) used in industry, having a mean δ 202Hg value of -0.42 ± 0.09‰ (1SD) and near-zero Δ 199Hg. On average, particulate fraction δ 202Hg values increased downstream by 0.53‰, while Δ 199Hg decreased by -0.10‰, converging with the Hg isotopic composition of the fine fraction of streambed sediment along the 26 km flow path. The dissolved fraction behaved differently. Although initial Δ 199Hg values of the dissolved fraction were also near-zero, these values increased transiently along the flow path. Initial δ 202Hg values of the dissolved fraction were more variable than in the particulate fraction, ranging from -0.44 to 0.18‰ among three seasonal sampling campaigns, but converged to an average δ 202Hg value of 0.01 ± 0.10‰ (1SD) downstream. Dissolved Hg in the hyporheic and riparian pore water had higher and lower δ 202Hg values, respectively, compared tomore » dissolved Hg in stream water. Finally, variations in Hg isotopic composition of the dissolved and suspended fractions along the flow path suggest that: (1) physical processes such as dilution and sedimentation do not fully explain decreases in total mercury concentrations along the flow path; (2) in-stream processes include photochemical reduction, but microbial reduction is likely more dominant; and (3) additional sources of dissolved mercury inputs to EFPC at baseflow during this study predominantly arise from the hyporheic zone.« less
Authors:
ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [2] ;  [1] ; ORCiD logo [2] ;  [2] ; ORCiD logo [2] ; ORCiD logo [2]
  1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Earth and Environmental Sciences
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division
Publication Date:
Grant/Contract Number:
AC05-00OR22725; SC0007042; AC05-000R22725
Type:
Accepted Manuscript
Journal Name:
Environmental Science: Processes & Impacts
Additional Journal Information:
Journal Volume: 2018; Journal Issue: none; Journal ID: ISSN 2050-7887
Publisher:
Royal Society of Chemistry
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Michigan, Ann Arbor, MI (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
07 ISOTOPE AND RADIATION SOURCES
OSTI Identifier:
1427599
Alternate Identifier(s):
OSTI ID: 1434077

Demers, Jason D., Blum, Joel D., Brooks, Scott C., Donovan, Patrick M., Riscassi, Ami L., Miller, Carrie L., Zheng, Wang, and Gu, Baohua. Hg isotopes reveal in-stream processing and legacy inputs in East Fork Poplar Creek, Oak Ridge, Tennessee, USA. United States: N. p., Web. doi:10.1039/C7EM00538E.
Demers, Jason D., Blum, Joel D., Brooks, Scott C., Donovan, Patrick M., Riscassi, Ami L., Miller, Carrie L., Zheng, Wang, & Gu, Baohua. Hg isotopes reveal in-stream processing and legacy inputs in East Fork Poplar Creek, Oak Ridge, Tennessee, USA. United States. doi:10.1039/C7EM00538E.
Demers, Jason D., Blum, Joel D., Brooks, Scott C., Donovan, Patrick M., Riscassi, Ami L., Miller, Carrie L., Zheng, Wang, and Gu, Baohua. 2018. "Hg isotopes reveal in-stream processing and legacy inputs in East Fork Poplar Creek, Oak Ridge, Tennessee, USA". United States. doi:10.1039/C7EM00538E.
@article{osti_1427599,
title = {Hg isotopes reveal in-stream processing and legacy inputs in East Fork Poplar Creek, Oak Ridge, Tennessee, USA},
author = {Demers, Jason D. and Blum, Joel D. and Brooks, Scott C. and Donovan, Patrick M. and Riscassi, Ami L. and Miller, Carrie L. and Zheng, Wang and Gu, Baohua},
abstractNote = {In this paper, natural abundance stable Hg isotope measurements were used to place new constraints on sources, transport, and transformations of Hg along the flow path of East Fork Poplar Creek (EFPC), a point-source contaminated headwater stream in Oak Ridge, Tennessee. Particulate-bound Hg in the water column of EFPC within the Y-12 National Security Complex, was isotopically similar to average metallic Hg(0) used in industry, having a mean δ202Hg value of -0.42 ± 0.09‰ (1SD) and near-zero Δ199Hg. On average, particulate fraction δ202Hg values increased downstream by 0.53‰, while Δ199Hg decreased by -0.10‰, converging with the Hg isotopic composition of the fine fraction of streambed sediment along the 26 km flow path. The dissolved fraction behaved differently. Although initial Δ199Hg values of the dissolved fraction were also near-zero, these values increased transiently along the flow path. Initial δ202Hg values of the dissolved fraction were more variable than in the particulate fraction, ranging from -0.44 to 0.18‰ among three seasonal sampling campaigns, but converged to an average δ202Hg value of 0.01 ± 0.10‰ (1SD) downstream. Dissolved Hg in the hyporheic and riparian pore water had higher and lower δ202Hg values, respectively, compared to dissolved Hg in stream water. Finally, variations in Hg isotopic composition of the dissolved and suspended fractions along the flow path suggest that: (1) physical processes such as dilution and sedimentation do not fully explain decreases in total mercury concentrations along the flow path; (2) in-stream processes include photochemical reduction, but microbial reduction is likely more dominant; and (3) additional sources of dissolved mercury inputs to EFPC at baseflow during this study predominantly arise from the hyporheic zone.},
doi = {10.1039/C7EM00538E},
journal = {Environmental Science: Processes & Impacts},
number = none,
volume = 2018,
place = {United States},
year = {2018},
month = {3}
}